PART I. BASIC SYSTEM CONFIGURATION
CHAPTER 1. GETTING STARTED
What Cockpit Is and Which Tasks It Can Be Used For
1.1. BASIC CONFIGURATION OF THE ENVIRONMENT
1.1.1. Introduction to Configuring the Date and Time
Displaying the Current Date and Time
1.1.2. Introduction to Configuring the System Locale
1.1.3. Introduction to Configuring the Keyboard Layout
1.2. CONFIGURING AND INSPECTING NETWORK ACCESS
1.2.1. Configuring Network Access During the Installation Process
1.2.2. Managing Network Connections After the Installation Process Using nmcli
1.2.3. Managing Network Connections After the Installation Process Using nmtui
1.2.4. Managing Networking in Cockpit
1.3. THE BASICS OF REGISTERING THE SYSTEM AND MANAGING SUBSCRIPTIONS
1.3.1. What Red Hat Subscriptions Are and Which Tasks They Can Be Used For
1.3.2. Registering the System During the Installation
1.3.3. Registering the System after the Installation
1.3.4. Registering a System to EUS Content
1.3.5. Registering a System to E4S Content
1.4. INSTALLING SOFTWARE
1.4.1. Prerequisites for Software Installation
1.4.2. Introduction to the System of Software Packaging and Software Repositories
1.4.3. Managing Basic Software Installation Tasks with Subscription Manager and Yum
1.5. MAKING SYSTEMD SERVICES START AT BOOT TIME
1.5.1. Enabling or Disabling the Services
1.5.2. Managing Services in Cockpit
1.5.3. Additional Resources on systemd Services
1.6. ENHANCING SYSTEM SECURITY WITH A FIREWALL, SELINUX AND SSH LOGINGS
1.6.1. Ensuring the Firewall Is Enabled and Running
1.6.1.1. What a Firewall Is and How It Enhances System Security
1.6.1.2. Re-enabling the firewalld Service
1.6.2. Ensuring the Appropriate State of SELinux
1.6.2.1. What SELinux Is and How It Enhances System Security
SELinux States
SELinux Modes
1.6.2.2. Ensuring the Required State of SELinux 35
1.6.2.3. Managing SELinux in Cockpit 36
1.6.3. Using SSH-based Authentication 36
1.6.3.1. What SSH-based Authentication Is and How It Enhances System Security
1.6.3.2. Establishing an SSH Connection
1.6.3.3. Disabling SSH Root Login 37
1.7. THE BASICS OF MANAGING USER ACCOUNTS 37
Normal and System Accounts
What Groups Are and Which Purposes They Can Be Used For
1.7.1. The Most Basic Command-Line Tools to Manage User Accounts and Groups
1.7.2. Managing User Accounts in Cockpit
1.8. DUMPING THE CRASHED KERNEL USING THE KDUMP MECHANISM
1.8.1. What kdump Is and Which Tasks It Can Be Used For
1.8.2. Enabling and Activating kdump During the Installation Process
1.8.3. Ensuring That kdump Is Installed and Enabled after the Installation Process
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CHAPTER 2 SYSTEM LOCALE AND KEYBOARD CONFIGURATION
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CHAPTER 3 CONFIGURING THE DATE AND TIME
51
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CHAPTER 4 MANAGING USERS AND GROUPS
60
1.8.4. Configuring kdump in Cockpit 40
1.8.5. Additional Resources on kdump 41
1.9. PERFORMING SYSTEM RESCUE AND CREATING SYSTEM BACKUP WITH REAR 41
1.9.1. What ReaR Is and Which Tasks It Can Be Used For 41
1.9.2. Quickstart to Installation and Configuration of ReaR 41
1.9.3. Quickstart to Creation of the Rescue System with ReaR 42
1.9.4. Quickstart to Configuration of ReaR with the Backup Software 42
1.10. USING THE LOG FILES TO TROUBLESHOOT PROBLEMS 42
1.10.1. Services Handling the syslog Messages 42
1.10.2. Subdirectories Storing the syslog Messages 43
1.11. ACCESSING RED HAT SUPPORT 43
1.11.1. Obtaining Red Hat Support Through Red Hat Customer Portal 43
1.11.1.1. What the Red Hat Support Tool Is and Which Tasks It Can Be Used For 43
1.11.2. Using the SOS Report to Troubleshoot Problems 44
2.1. SETTING THE SYSTEM LOCALE 45
2.1.1. Displaying the Current Status 45
2.1.2. Listing Available Locales 46
2.1.3. Setting the Locale 46
2.1.4. Making System Locale Settings Permanent when Installing with Kickstart 47
2.2. CHANGING THE KEYBOARD LAYOUT 48
2.2.1. Displaying the Current Settings 48
2.2.2. Listing Available Keymaps 48
2.2.3. Setting the Keymap 48
2.3. ADDITIONAL RESOURCES 49
Installed Documentation 49
See Also 49
3.1. USING THE TIMEDATECTL COMMAND 51
3.1.1. Displaying the Current Date and Time 51
3.1.2. Changing the Current Time 52
3.1.3. Changing the Current Date 52
3.1.4. Changing the Time Zone 53
3.1.5. Synchronizing the System Clock with a Remote Server 53
3.2. USING THE DATE COMMAND 54
3.2.1. Displaying the Current Date and Time 54
3.2.2. Changing the Current Time 55
3.2.3. Changing the Current Date 56
3.3. USING THE HWCLOCK COMMAND 56
3.3.1. Displaying the Current Date and Time 57
3.3.2. Setting the Date and Time 57
3.3.3. Synchronizing the Date and Time 57
3.4. ADDITIONAL RESOURCES 58
Installed Documentation 58
See Also 58
4.1. INTRODUCTION TO USERS AND GROUPS 60
Reserved User and Group IDs 60
4.1.1. User Private Groups 60
4.1.2. Shadow Passwords 61
4.2. MANAGING USERS IN A GRAPHICAL ENVIRONMENT 61
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CHAPTER 5 ACCESS CONTROL LISTS
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CHAPTER 6 GAINING PRIVILEGES
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PART II. SUBSCRIPTION AND SUPPORT
CHAPTER 7 REGISTERING THE SYSTEM AND MANAGING SUBSCRIPTIONS
83
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CHAPTER 8 ACCESSING SUPPORT USING THE RED HAT SUPPORT TOOL
87
4.2.1. Using the Users Settings Tool 61
4.3. USING COMMAND-LINE TOOLS 63
4.3.1. Adding a New User 64
4.3.2. Adding a New Group 67
4.3.3. Adding an Existing User to an Existing Group 68
4.3.4. Creating Group Directories 68
4.3.5. Setting Default Permissions for New Files Using umask 69
What umask consists of 69
How umask works 69
4.3.5.1. Managing umask in Shells 70
Displaying the current mask 70
Setting mask in shell using umask 71
Working with the default shell umask 71
Working with the default shell umask of a specific user 72
Setting default permissions for newly created home directories 72
4.4. ADDITIONAL RESOURCES 72
Installed Documentation 72
Online Documentation 73
See Also 73
5.1. MOUNTING FILE SYSTEMS 74
5.1.1. NFS 74
5.2. SETTING ACCESS ACLS 74
5.3. SETTING DEFAULT ACLS 76
5.4. RETRIEVING ACLS 76
5.5. ARCHIVING FILE SYSTEMS WITH ACLS 76
5.6. COMPATIBILITY WITH OLDER SYSTEMS 77
5.7. ACL REFERENCES 78
6.1. CONFIGURING ADMINISTRATIVE ACCESS USING THE SU UTILITY 79
6.2. CONFIGURING ADMINISTRATIVE ACCESS USING THE SUDO UTILITY 80
6.3. ADDITIONAL RESOURCES 82
Installed Documentation 82
Online Documentation 82
See Also 82
7.1. REGISTERING THE SYSTEM AND ATTACHING SUBSCRIPTIONS 84
7.2. MANAGING SOFTWARE REPOSITORIES 84
7.3. REMOVING SUBSCRIPTIONS 85
7.4. ADDITIONAL RESOURCES 86
Installed Documentation 86
Related Books 86
See Also 86
8.1. INSTALLING THE RED HAT SUPPORT TOOL 87
8.2. REGISTERING THE RED HAT SUPPORT TOOL USING THE COMMAND LINE 87
8.3. USING THE RED HAT SUPPORT TOOL IN INTERACTIVE SHELL MODE 87
8.4. CONFIGURING THE RED HAT SUPPORT TOOL 87
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PART III INSTALLING AND MANAGING SOFTWARE
CHAPTER 9 YUM
92
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8.4.1. Saving Settings to the Configuration Files 88
8.5. OPENING AND UPDATING SUPPORT CASES USING INTERACTIVE MODE 89
8.6. VIEWING SUPPORT CASES ON THE COMMAND LINE 91
8.7. ADDITIONAL RESOURCES 91
9.1. CHECKING FOR AND UPDATING PACKAGES 93
9.1.1. Checking For Updates 93
9.1.2. Updating Packages 94
Updating a Single Package 94
9.1.3. Upgrading the System Off-line with ISO and Yum 96
9.2. WORKING WITH PACKAGES 98
9.2.1. Searching Packages 98
9.2.2. Listing Packages 99
9.2.3. Displaying Package Information 101
9.2.4. Installing Packages 102
9.2.5. Downloading Packages 105
9.2.6. Removing Packages 106
9.3. WORKING WITH PACKAGE GROUPS 106
9.3.1. Listing Package Groups 107
9.3.2. Installing a Package Group 108
9.3.3. Removing a Package Group 109
9.4. WORKING WITH TRANSACTION HISTORY 110
9.4.1. Listing Transactions 110
9.4.2. Examining Transactions 114
9.4.3. Reverting and Repeating Transactions 115
9.4.4. Starting New Transaction History 116
9.5. CONFIGURING YUM AND YUM REPOSITORIES 116
9.5.1. Setting [main] Options 117
9.5.2. Setting [repository] Options 120
9.5.3. Using Yum Variables 122
9.5.4. Viewing the Current Configuration 123
9.5.5. Adding, Enabling, and Disabling a Yum Repository 124
9.5.6. Creating a Yum Repository 126
9.5.6.1. Adding packages to an already created yum repository 127
9.5.7. Adding the Optional and Supplementary Repositories 127
9.6. YUM PLUG-INS 127
9.6.1. Enabling, Configuring, and Disabling Yum Plug-ins 128
9.6.2. Installing Additional Yum Plug-ins 128
9.6.3. Working with Yum Plug-ins
9.7. AUTOMATICALLY REFRESHING PACKAGE DATABASE AND DOWNLOADING UPDATES WITH YUM
CRON 129
9.7.1. Enabling Automatic Installation of Updates 131
9.7.2. Setting up Optional Email Notifications 131
9.7.3. Enabling or Disabling Specific Repositories 132
9.7.4. Testing Yum-cron Settings 132
9.7.5. Disabling Yum-cron messages 132
9.7.6. Automatically Cleaning Packages 133
9.8. ADDITIONAL RESOURCES 133
Installed Documentation 133
Online Resources 133
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PART IV. INFRASTRUCTURE SERVICES
CHAPTER 10 MANAGING SERVICES WITH SYSTEMD
134
135
See Also 133
10.1. INTRODUCTION TO SYSTEMD 135
Overriding the Default systemd Configuration Using system.conf 136
10.1.1. Main Features 136
10.1.2. Compatibility Changes 137
10.2. MANAGING SYSTEM SERVICES 138
Specifying Service Units 139
Behavior of systemctl in a chroot Environment 140
10.2.1. Listing Services 140
10.2.2. Displaying Service Status 141
10.2.3. Starting a Service 143
10.2.4. Stopping a Service 143
10.2.5. Restarting a Service 144
10.2.6. Enabling a Service 144
10.2.7. Disabling a Service 145
10.2.8. Starting a Conflicting Service 146
10.3. WORKING WITH SYSTEMD TARGETS 146
10.3.1. Viewing the Default Target 147
10.3.2. Viewing the Current Target 147
10.3.3. Changing the Default Target 148
10.3.4. Changing the Current Target 149
10.3.5. Changing to Rescue Mode 149
10.3.6. Changing to Emergency Mode 150
10.4. SHUTTING DOWN, SUSPENDING, AND HIBERNATING THE SYSTEM 150
10.4.1. Shutting Down the System 151
Using systemctl Commands 151
Using the shutdown Command 151
10.4.2. Restarting the System 152
10.4.3. Suspending the System 152
10.4.4. Hibernating the System 152
10.5. CONTROLLING SYSTEMD ON A REMOTE MACHINE 153
10.6. CREATING AND MODIFYING SYSTEMD UNIT FILES 153
10.6.1. Understanding the Unit File Structure 154
10.6.2. Creating Custom Unit Files 158
10.6.3. Converting SysV Init Scripts to Unit Files 162
Finding the Service Description 162
Finding Service Dependencies 162
Finding Default Targets of the Service 163
Finding Files Used by the Service 163
10.6.4. Modifying Existing Unit Files 165
Extending the Default Unit Configuration 165
Overriding the Default Unit Configuration 167
Monitoring Overriden Units 168
10.6.5. Working with Instantiated Units 169
10.7. ADDITIONAL CONSIDERATIONS WHILE MANAGING SERVICES 170
10.8. ADDITIONAL RESOURCES 172
Installed Documentation 173
Online Documentation 173
See Also 174
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CHAPTER 12. OPENSSH
182
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CHAPTER 13. TIGERVNC
200
11.1. CONFIGURING THE BRLTTY SERVICE 175
Enable the brltty Service 175
Authorize Users to Use the Braille Display 175
Set the Braille Driver 176
Set the Braille Device 177
Set Specific Parameters for Particular Braille Displays 177
Set the Text Table 178
Set the Contraction Table 178
11.2. SWITCH ON ALWAYS SHOW UNIVERSAL ACCESS MENU 178
11.3. ENABLING THE FESTIVAL SPEECH SYNTHESIS SYSTEM 179
Choose a Voice for Festival 180
12.1. THE SSH PROTOCOL 182
12.1.1. Why Use SSH? 182
12.1.2. Main Features 182
12.1.3. Protocol Versions 183
12.1.4. Event Sequence of an SSH Connection 183
12.1.4.1. Transport Layer 183
12.1.4.2. Authentication 184
12.1.4.3. Channels 185
12.2. CONFIGURING OPENSSH 185
12.2.1. Configuration Files 185
12.2.2. Starting an OpenSSH Server 187
12.2.3. Requiring SSH for Remote Connections 188
12.2.4. Using Key-based Authentication 188
12.2.4.1. Generating Key Pairs 189
12.2.4.2. Configuring ssh-agent 191
12.3. OPENSSH CLIENTS 193
12.3.1. Using the ssh Utility 194
12.3.2. Using the scp Utility 195
12.3.3. Using the sftp Utility 196
12.4. MORE THAN A SECURE SHELL 197
12.4.1. X11 Forwarding 197
12.4.2. Port Forwarding 197
12.5. ADDITIONAL RESOURCES 198
Installed Documentation 199
Online Documentation 199
See Also 199
13.1. VNC SERVER 200
13.1.1. Installing VNC Server 200
13.1.2. Configuring VNC Server 200
13.1.2.1. Configuring VNC Server for Two Users 201
13.1.3. Starting VNC Server 201
13.1.3.1. Configuring VNC Server for Two Users and Two Different Displays 202
13.1.4. VNC setup based on xinetd with XDMCP for GDM 202
13.1.5. Terminating a VNC Session 204
13.2. SHARING AN EXISTING DESKTOP 204
13.3. VNC VIEWER 204
13.3.1. Installing VNC Viewer 205
CHAPTER 11. CONFIGURING A SYSTEM FOR ACCESSIBILITY
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PART V. SERVERS
CHAPTER 14. WEB SERVERS
209
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CHAPTER 15. MAIL SERVERS
233
13.3.2. Connecting to VNC Server 205
13.3.2.1. Configuring the Firewall for VNC 205
13.3.3. Connecting to VNC Server Using SSH 207
Restricting VNC Access 207
13.4. ADDITIONAL RESOURCES 207
Installed Documentation 207
14.1. THE APACHE HTTP SERVER 210
14.1.1. Notable Changes 210
14.1.2. Updating the Configuration 213
14.1.3. Running the httpd Service 213
14.1.3.1. Starting the Service 213
14.1.3.2. Stopping the Service 214
14.1.3.3. Restarting the Service 214
14.1.3.4. Verifying the Service Status 214
14.1.4. Editing the Configuration Files 215
14.1.5. Working with Modules 215
14.1.5.1. Loading a Module 215
14.1.5.2. Writing a Module 215
14.1.6. Setting Up Virtual Hosts 216
14.1.7. Setting Up an SSL Server 216
14.1.7.1. An Overview of Certificates and Security 217
14.1.8. Enabling the mod_ssl Module 218
14.1.8.1. Enabling and Disabling SSL and TLS in mod_ssl 218
14.1.9. Enabling the mod_nss Module 220
14.1.9.1. Enabling and Disabling SSL and TLS in mod_nss 224
14.1.10. Using an Existing Key and Certificate 226
14.1.11. Generating a New Key and Certificate 227
14.1.12. Configure the Firewall for HTTP and HTTPS Using the Command Line 231
14.1.12.1. Checking Network Access for Incoming HTTPS and HTTPS Using the Command Line 232
14.1.13. Additional Resources 232
Installed Documentation 232
Installable Documentation 232
Online Documentation 232
15.1. EMAIL PROTOCOLS 233
15.1.1. Mail Transport Protocols 233
15.1.1.1. SMTP 233
15.1.2. Mail Access Protocols 233
15.1.2.1. POP 233
15.1.2.2. IMAP 234
15.1.2.3. Dovecot 235
15.2. EMAIL PROGRAM CLASSIFICATIONS 236
15.2.1. Mail Transport Agent 236
15.2.2. Mail Delivery Agent 237
15.2.3. Mail User Agent 237
15.3. MAIL TRANSPORT AGENTS 237
15.3.1. Postfix 237
15.3.1.1. The Default Postfix Installation 238
15.3.1.2. Upgrading From a Previous Release 238
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CHAPTER 16. FILE AND PRINT SERVERS
261
15.3.1.3. Basic Postfix Configuration 239
15.3.1.4. Using Postfix with LDAP 239
15.3.1.4.1. The /etc/aliases lookup example 239
15.3.2. Sendmail 240
15.3.2.1. Purpose and Limitations 240
15.3.2.2. The Default Sendmail Installation 240
15.3.2.3. Common Sendmail Configuration Changes 241
15.3.2.4. Masquerading 242
15.3.2.5. Stopping Spam 243
15.3.2.6. Using Sendmail with LDAP 243
15.3.3. Fetchmail 244
15.3.3.1. Fetchmail Configuration Options 245
15.3.3.2. Global Options 246
15.3.3.3. Server Options 246
15.3.3.4. User Options 246
15.3.3.5. Fetchmail Command Options 247
15.3.3.6. Informational or Debugging Options 247
15.3.3.7. Special Options 248
15.3.4. Mail Transport Agent (MTA) Configuration 248
15.4. MAIL DELIVERY AGENTS 248
15.4.1. Procmail Configuration 249
15.4.2. Procmail Recipes 250
15.4.2.1. Delivering vs. Non-Delivering Recipes 250
15.4.2.2. Flags 251
15.4.2.3. Specifying a Local Lockfile 251
15.4.2.4. Special Conditions and Actions 252
15.4.2.5. Recipe Examples 252
15.4.2.6. Spam Filters 253
15.5. MAIL USER AGENTS 255
15.5.1. Securing Communication 255
15.5.1.1. Secure Email Clients 255
15.5.1.2. Securing Email Client Communications 255
15.6. CONFIGURING MAIL SERVER WITH ANTISPAM AND ANTIVIRUS 256
15.6.1. Configuring Spam Filtering for Mail Transport Agent or Mail Delivery Agent 256
15.6.1.1. Configuring Spam Filtering in a Mail Transport Agent 256
15.6.1.2. Configuring Spam Filtering in a Mail Delivery Agent 257
15.6.2. Configuring Antivirus Protection 257
15.6.3. Using the EPEL Repository to install Antispam and Antivirus Software 258
15.7. ADDITIONAL RESOURCES 258
15.7.1. Installed Documentation 258
15.7.2. Online Documentation 259
15.7.3. Related Books 259
16.1. SAMBA 261
16.1.1. The Samba Services 261
16.1.2. Verifying the smb.conf File by Using the testparm Utility 262
16.1.3. Understanding the Samba Security Modes 263
16.1.4. Setting up Samba as a Standalone Server 263
16.1.4.1. Setting up the Server Configuration for the Standalone Server 263
16.1.4.2. Creating and Enabling Local User Accounts 264
16.1.5. Setting up Samba as a Domain Member 265
16.1.5.1. Joining a Domain 265
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16.1.5.2. Verifying That Samba Was Correctly Joined As a Domain Member
Verifying That the Operating System Can Retrieve Domain User Accounts and Groups
Verifying If AD Domain Users Can Obtain a Kerberos Ticket
Listing the Available Domains
16.1.5.3. Understanding ID Mapping
16.1.5.3.1. Planning ID Ranges
16.1.5.3.2. The * Default Domain
16.1.5.4. The Different ID Mapping Back Ends
16.1.5.4.1. Using the tdb ID Mapping Back End
16.1.5.4.2. Using the ad ID Mapping Back End
16.1.5.4.3. Using the rid ID Mapping Back End
16.1.5.4.4. Using the autorid ID Mapping Back End
16.1.6. Configuring File Shares on a Samba Server
16.1.6.1. Setting up a Share That Uses POSIX ACLs
16.1.6.1.1. Adding a Share That Uses POSIX ACLs
16.1.6.1.2. Setting ACLs
16.1.6.1.3. Setting Permissions on a Share
16.1.6.2. Setting up a Share That Uses Windows ACLs
16.1.6.2.1. Granting the SeDiskOperatorPrivilege Privilege
16.1.6.2.2. Enabling Windows ACL Support
16.1.6.2.3. Adding a Share That Uses Windows ACLs
16.1.6.2.4. Managing Share Permissions and File System ACLs of a Share That Uses Windows ACLs
16.1.6.3. Managing ACLs on an SMB Share Using smbcacls
16.1.6.3.1. Understanding Access Control Entries
16.1.6.3.2. Displaying ACLs Using smbcacls
16.1.6.3.3. Calculating an ACE Mask
16.1.6.3.4. Adding, Updating, And Removing an ACL Using smbcacls
16.1.6.4. Enabling Users to Share Directories on a Samba Server
16.1.6.4.1. Enabling the User Shares Feature
16.1.6.4.2. Adding a User Share
16.1.6.4.3. Updating Settings of a User Share
16.1.6.4.4. Displaying Information About Existing User Shares
16.1.6.4.5. Listing User Shares
16.1.6.4.6. Deleting a User Share
16.1.6.5. Enabling Guest Access to a Share
16.1.7. Setting up a Samba Print Server
16.1.7.1. The Samba spoolssd Service
16.1.7.2. Enabling Print Server Support in Samba
16.1.7.3. Manually Sharing Specific Printers
16.1.7.4. Setting up Automatic Printer Driver Downloads for Windows Clients
16.1.7.4.1. Basic Information about Printer Drivers
16.1.7.4.2. Enabling Users to Upload and Preconfigure Drivers
16.1.7.4.3. Setting up the print$ Share
16.1.7.4.4. Creating a GPO to Enable Clients to Trust the Samba Print Server
16.1.7.4.5. Uploading Drivers and Preconfiguring Printers
16.1.8. Tuning the Performance of a Samba Server
16.1.8.1. Setting the SMB Protocol Version
16.1.8.2. Tuning Shares with Directories That Contain a Large Number of Files
16.1.8.3. Settings That Can Have a Negative Performance Impact
16.1.9. Frequently Used Samba Command-line Utilities
16.1.9.1. Using the net Utility
16.1.9.1.1. Using the net ads join and net rpc join Commands
16.1.9.1.2. Using the net rpc rights Command
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CHAPTER 17. DATABASE SERVERS
341
16.1.9.1.3. Using the net rpc share Command 307
16.1.9.1.4. Using the net user Command 308
16.1.9.1.5. Using the net usershare Command 309
16.1.9.2. Using the rpcclient Utility 309
16.1.9.3. Using the samba-regedit Application 310
16.1.9.4. Using the smbcacls Utility 311
16.1.9.5. Using the smbclient Utility 311
16.1.9.5.1. Using smbclient in Interactive Mode 311
16.1.9.5.2. Using smbclient in Scripting Mode 312
16.1.9.6. Using the smbcontrol Utility 312
16.1.9.7. Using the smbpasswd Utility 313
16.1.9.8. Using the smbstatus Utility 313
16.1.9.9. Using the smbtar Utility 314
16.1.9.10. Using the testparm Utility 314
16.1.9.11. Using the wbinfo Utility 314
16.1.10. Additional Resources 315
16.2. FTP 316
16.2.1. The File Transfer Protocol 316
16.2.2. The vsftpd Server 316
16.2.2.1. Starting and Stopping vsftpd 317
16.2.2.2. Starting Multiple Copies of vsftpd 318
16.2.2.3. Encrypting vsftpd Connections Using TLS 319
16.2.2.4. SELinux Policy for vsftpd 320
16.2.3. Additional Resources 320
16.2.3.1. Installed Documentation 320
16.2.3.2. Online Documentation 321
16.3. PRINT SETTINGS 322
16.3.1. Starting the Print Settings Configuration Tool 323
16.3.2. Starting Printer Setup 323
16.3.3. Adding a Local Printer 324
16.3.4. Adding an AppSocket/HP JetDirect printer 325
16.3.5. Adding an IPP Printer 326
16.3.6. Adding an LPD/LPR Host or Printer 327
16.3.7. Adding a Samba (SMB) printer 328
16.3.8. Selecting the Printer Model and Finishing 330
16.3.9. Printing a Test Page 333
16.3.10. Modifying Existing Printers 333
16.3.10.1. The Settings Page 333
16.3.10.2. The Policies Page 334
16.3.10.2.1. Sharing Printers 334
16.3.10.2.2. The Access Control Page 336
16.3.10.2.3. The Printer Options Page 336
16.3.10.2.4. Job Options Page 337
16.3.10.2.5. Ink/Toner Levels Page 338
16.3.10.3. Managing Print Jobs 339
16.3.11. Additional Resources 340
Installed Documentation 340
Online Documentation 340
17.1. MARIADB 341
17.1.1. Installing the MariaDB server 341
17.1.1.1. Improving MariaDB installation security 341
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CHAPTER 18. CONFIGURING NTP USING THE CHRONY SUITE
344
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CHAPTER 19. CONFIGURING NTP USING NTPD
363
17.1.2. Configuring the MariaDB server for networking 342
17.1.3. Backing up MariaDB data 342
17.1.3.1. Logical back up 342
17.1.3.2. Physical back up 342
18.1. INTRODUCTION TO THE CHRONY SUITE 344
18.1.1. Differences Between ntpd and chronyd 344
18.1.2. Choosing Between NTP Daemons 345
18.2. UNDERSTANDING CHRONY AND ITS CONFIGURATION 346
18.2.1. Understanding chronyd and chronyc 346
18.2.2. Understanding the chrony Configuration Commands 346
18.2.3. Security with chronyc 350
18.3. USING CHRONY 351
18.3.1. Installing chrony 351
18.3.2. Checking the Status of chronyd 352
18.3.3. Starting chronyd 352
18.3.4. Stopping chronyd 352
18.3.5. Checking if chrony is Synchronized 352
18.3.5.1. Checking chrony Tracking 352
18.3.5.2. Checking chrony Sources 354
18.3.5.3. Checking chrony Source Statistics 355
18.3.6. Manually Adjusting the System Clock 356
18.4. SETTING UP CHRONY FOR DIFFERENT ENVIRONMENTS 356
18.4.1. Setting Up chrony for a System in an Isolated Network 356
18.5. USING CHRONYC 357
18.5.1. Using chronyc to Control chronyd 357
18.6. CHRONY WITH HW TIMESTAMPING 358
18.6.1. Understanding Hardware Timestamping 358
18.6.2. Verifying Support for Hardware Timestamping 358
18.6.3. Enabling Hardware Timestamping 359
18.6.4. Configuring Client Polling Interval 359
18.6.5. Enabling Interleaved Mode 359
18.6.6. Configuring Server for Large Number of Clients 359
18.6.7. Verifying Hardware Timestamping 360
18.6.8. Configuring PTP-NTP bridge 361
18.7. ADDITIONAL RESOURCES 361
18.7.1. Installed Documentation 361
18.7.2. Online Documentation 361
19.1. INTRODUCTION TO NTP 363
19.2. NTP STRATA 363
19.3. UNDERSTANDING NTP 364
19.4. UNDERSTANDING THE DRIFT FILE 365
19.5. UTC, TIMEZONES, AND DST 365
19.6. AUTHENTICATION OPTIONS FOR NTP 365
19.7. MANAGING THE TIME ON VIRTUAL MACHINES 366
19.8. UNDERSTANDING LEAP SECONDS 366
19.9. UNDERSTANDING THE NTPD CONFIGURATION FILE 366
19.10. UNDERSTANDING THE NTPD SYSCONFIG FILE 368
19.11. DISABLING CHRONY 368
19.12. CHECKING IF THE NTP DAEMON IS INSTALLED 369
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CHAPTER 20. CONFIGURING PTP USING PTP4L
381
19.13. INSTALLING THE NTP DAEMON (NTPD) 369
19.14. CHECKING THE STATUS OF NTP 369
19.15. CONFIGURE THE FIREWALL TO ALLOW INCOMING NTP PACKETS 369
19.15.1. Change the Firewall Settings 370
19.15.2. Open Ports in the Firewall for NTP Packets 370
19.16. CONFIGURE NTPDATE SERVERS 370
19.17. CONFIGURE NTP 371
19.17.1. Configure Access Control to an NTP Service 371
19.17.2. Configure Rate Limiting Access to an NTP Service 372
19.17.3. Adding a Peer Address 372
19.17.4. Adding a Server Address 373
19.17.5. Adding a Broadcast or Multicast Server Address 373
19.17.6. Adding a Manycast Client Address 373
19.17.7. Adding a Broadcast Client Address 374
19.17.8. Adding a Manycast Server Address 374
19.17.9. Adding a Multicast Client Address 374
19.17.10. Configuring the Burst Option 374
19.17.11. Configuring the iburst Option 375
19.17.12. Configuring Symmetric Authentication Using a Key 375
19.17.13. Configuring the Poll Interval 375
19.17.14. Configuring Server Preference 376
19.17.15. Configuring the Time-to-Live for NTP Packets 376
19.17.16. Configuring the NTP Version to Use 376
19.18. CONFIGURING THE HARDWARE CLOCK UPDATE 376
19.19. CONFIGURING CLOCK SOURCES 378
19.20. ADDITIONAL RESOURCES 379
19.20.1. Installed Documentation 379
19.20.2. Useful Websites 379
20.1. INTRODUCTION TO PTP 381
20.1.1. Understanding PTP 381
20.1.2. Advantages of PTP 382
20.2. USING PTP 383
20.2.1. Checking for Driver and Hardware Support 383
20.2.2. Installing PTP 383
20.2.3. Starting ptp4l 384
Starting ptp4l as a Service 384
Using ptp4l From The Command Line 384
Logging Messages From ptp4l 385
20.2.3.1. Selecting a Delay Measurement Mechanism 385
20.3. USING PTP WITH MULTIPLE INTERFACES 385
20.4. SPECIFYING A CONFIGURATION FILE 387
20.5. USING THE PTP MANAGEMENT CLIENT 387
20.6. SYNCHRONIZING THE CLOCKS 388
20.7. VERIFYING TIME SYNCHRONIZATION 389
20.8. SERVING PTP TIME WITH NTP 391
20.9. SERVING NTP TIME WITH PTP 392
20.10. SYNCHRONIZE TO PTP OR NTP TIME USING TIMEMASTER 392
20.10.1. Starting timemaster as a Service 392
20.10.2. Understanding the timemaster Configuration File 393
20.10.3. Configuring timemaster Options 395
20.11. IMPROVING ACCURACY 396
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PART VI. MONITORING AND AUTOMATION
CHAPTER 21. SYSTEM MONITORING TOOLS
398
399
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CHAPTER 22 OPENLMI
428
20.12. ADDITIONAL RESOURCES 396
20.12.1. Installed Documentation 396
20.12.2. Useful Websites 396
21.1. VIEWING SYSTEM PROCESSES 399
21.1.1. Using the ps Command 399
21.1.2. Using the top Command 400
21.1.3. Using the System Monitor Tool 401
21.2. VIEWING MEMORY USAGE 402
21.2.1. Using the free Command 402
21.2.2. Using the System Monitor Tool 403
21.3. VIEWING CPU USAGE 404
21.3.1. Using the System Monitor Tool 404
21.4. VIEWING BLOCK DEVICES AND FILE SYSTEMS 404
21.4.1. Using the lsblk Command 404
21.4.2. Using the blkid Command 405
21.4.3. Using the findmnt Command 406
21.4.4. Using the df Command 407
21.4.5. Using the du Command 408
21.4.6. Using the System Monitor Tool 409
21.5. VIEWING HARDWARE INFORMATION 409
21.5.1. Using the lspci Command 409
21.5.2. Using the lsusb Command 410
21.5.3. Using the lscpu Command 411
21.6. CHECKING FOR HARDWARE ERRORS 412
21.7. MONITORING PERFORMANCE WITH NET-SNMP 413
21.7.1. Installing Net-SNMP 413
21.7.2. Running the Net-SNMP Daemon 414
21.7.2.1. Starting the Service 414
21.7.2.2. Stopping the Service 414
21.7.2.3. Restarting the Service 415
21.7.3. Configuring Net-SNMP 415
21.7.3.1. Setting System Information 415
21.7.3.2. Configuring Authentication 416
Configuring SNMP Version 2c Community 416
Configuring SNMP Version 3 User 417
21.7.4. Retrieving Performance Data over SNMP 418
21.7.4.1. Hardware Configuration 418
21.7.4.2. CPU and Memory Information 419
21.7.4.3. File System and Disk Information 420
21.7.4.4. Network Information 421
21.7.5. Extending Net-SNMP 421
21.7.5.1. Extending Net-SNMP with Shell Scripts 422
21.7.5.2. Extending Net-SNMP with Perl 424
21.8. ADDITIONAL RESOURCES 426
21.8.1. Installed Documentation 427
22.1. ABOUT OPENLMI 428
22.1.1. Main Features 428
22.1.2. Management Capabilities 428
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22.2. INSTALLING OPENLMI
22.2.1. Installing OpenLMI on a Managed System
22.2.2. Installing OpenLMI on a Client System
22.3. CONFIGURING SSL CERTIFICATES FOR OPENPEGASUS
22.3.1. Managing Self-signed Certificates
22.3.2. Managing Authority-signed Certificates with Identity Management (Recommended)
22.3.3. Managing Authority-signed Certificates Manually
22.4. USING LMISHELL
22.4.1. Starting, Using, and Exiting LMIShell
Starting LMIShell in Interactive Mode
Using Tab Completion
Browsing History
Handling Exceptions
Configuring a Temporary Cache
Exiting LMIShell
Running an LMIShell Script
22.4.2. Connecting to a CIMOM
Connecting to a Remote CIMOM
Connecting to a Local CIMOM
Verifying a Connection to a CIMOM
22.4.3. Working with Namespaces
Listing Available Namespaces
Accessing Namespace Objects
22.4.4. Working with Classes
Listing Available Classes
Accessing Class Objects
Examining Class Objects
Listing Available Methods
Listing Available Properties
Listing and Viewing ValueMap Properties
Fetching a CIMClass Object
22.4.5. Working with Instances
Accessing Instances
Examining Instances
Creating New Instances
Deleting Individual Instances
Listing and Accessing Available Properties
Listing and Using Available Methods
Listing and Viewing ValueMap Parameters
Refreshing Instance Objects
Displaying MOF Representation
22.4.6. Working with Instance Names
Accessing Instance Names
Examining Instance Names
Creating New Instance Names
Listing and Accessing Key Properties
Converting Instance Names to Instances
22.4.7. Working with Associated Objects
Accessing Associated Instances
Accessing Associated Instance Names
22.4.8. Working with Association Objects
Accessing Association Instances
Accessing Association Instance Names
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CHAPTER 23. VIEWING AND MANAGING LOG FILES
474
22.4.9. Working with Indications 462
Subscribing to Indications 462
Listing Subscribed Indications 463
Unsubscribing from Indications 463
Implementing an Indication Handler 464
22.4.10. Example Usage 465
Using the OpenLMI Service Provider 465
Using the OpenLMI Networking Provider 466
Using the OpenLMI Storage Provider 468
Using the OpenLMI Hardware Provider 470
22.5. USING OPENLMI SCRIPTS 471
22.6. ADDITIONAL RESOURCES 472
Installed Documentation 472
Online Documentation 472
See Also 472
23.1. LOCATING LOG FILES 474
23.2. BASIC CONFIGURATION OF RSYSLOG 474
23.2.1. Filters 475
23.2.2. Actions 478
Specifying Multiple Actions 482
23.2.3. Templates 483
Generating Dynamic File Names 484
Properties 484
Template Examples 485
23.2.4. Global Directives 488
23.2.5. Log Rotation 488
23.2.6. Increasing the Limit of Open Files 490
23.3. USING THE NEW CONFIGURATION FORMAT 490
23.3.1. Rulesets 491
23.3.2. Compatibility with sysklogd 492
23.4. WORKING WITH QUEUES IN RSYSLOG 492
23.4.1. Defining Queues 494
Direct Queues 494
Disk Queues 494
In-memory Queues 495
Disk-Assisted In-memory Queues 495
23.4.2. Creating a New Directory for rsyslog Log Files 497
23.4.3. Managing Queues 498
Limiting Queue Size 498
Discarding Messages 498
Using Timeframes 499
Configuring Worker Threads 499
Batch Dequeuing 499
Terminating Queues 500
23.4.4. Using the New Syntax for rsyslog queues 500
23.5. CONFIGURING RSYSLOG ON A LOGGING SERVER 501
23.5.1. Using The New Template Syntax on a Logging Server 504
23.6. USING RSYSLOG MODULES 505
23.6.1. Importing Text Files 506
23.6.2. Exporting Messages to a Database 507
23.6.3. Enabling Encrypted Transport 507
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CHAPTER 24. AUTOMATING SYSTEM TASKS
528
Configuring Encrypted Message Transfer with TLS 508
Configuring Encrypted Message Transfer with GSSAPI 509
23.6.4. Using RELP 510
Configuring RELP 510
Configuring RELP with TLS 511
23.7. INTERACTION OF RSYSLOG AND JOURNAL 512
23.8. STRUCTURED LOGGING WITH RSYSLOG 513
23.8.1. Importing Data from Journal 514
23.8.2. Filtering Structured Messages 515
23.8.3. Parsing JSON 515
23.8.4. Storing Messages in the MongoDB 515
23.9. DEBUGGING RSYSLOG 516
23.10. USING THE JOURNAL 516
23.10.1. Viewing Log Files 516
23.10.2. Access Control 518
23.10.3. Using The Live View 518
23.10.4. Filtering Messages 519
Filtering by Priority 519
Filtering by Time 519
Advanced Filtering 519
23.10.5. Enabling Persistent Storage 521
23.11. MANAGING LOG FILES IN A GRAPHICAL ENVIRONMENT 521
23.11.1. Viewing Log Files 521
23.11.2. Adding a Log File 524
23.11.3. Monitoring Log Files 525
23.12. ADDITIONAL RESOURCES 526
Installed Documentation 526
Installable Documentation 526
Online Documentation 527
See Also 527
24.1. SCHEDULING A RECURRING JOB USING CRON 528
24.1.1. Prerequisites for Cron Jobs 528
24.1.2. Scheduling a Cron Job 529
Scheduling a Job as root User 529
Scheduling a Job as Non-root User 530
Scheduling Hourly, Daily, Weekly, and Monthly Jobs 530
24.2. SCHEDULING A RECURRING ASYNCHRONOUS JOB USING ANACRON 531
24.2.1. Prerequisites for Anacrob Jobs 531
24.2.2. Scheduling an Anacron Job 532
Scheduling an anacron Job as root User 532
Scheduling Hourly, Daily, Weekly, and Monthly Jobs 533
24.3. SCHEDULING A JOB TO RUN AT A SPECIFIC TIME USING AT 533
24.3.1. Prerequisites for At Jobs 533
24.3.2. Scheduling an At Job 533
Viewing Pending Jobs 534
Deleting a Scheduled Job 534
24.3.2.1. Controlling Access to At and Batch 535
24.4. SCHEDULING A JOB TO RUN ON SYSTEM LOAD DROP USING BATCH 535
24.4.1. Prerequisites for Batch Jobs 535
24.4.2. Scheduling a Batch Job 535
Changing the Default System Load Average Limit 536
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CHAPTER 25. AUTOMATIC BUG REPORTING TOOL (ABRT)
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PART VII KERNEL CUSTOMIZATION WITH BOOTLOADER
CHAPTER 26. WORKING WITH GRUB 2
Viewing Pending Jobs 536
Deleting a Scheduled Job 536
Controlling Access to Batch 536
24.5. SCHEDULING A JOB TO RUN ON NEXT BOOT USING A SYSTEMD UNIT FILE 536
24.6. ADDITIONAL RESOURCES 538
Installed Documentation 538
25.1. INTRODUCTION TO ABRT 539
25.2. INSTALLING ABRT AND STARTING ITS SERVICES 539
25.2.1. Installing the ABRT GUI 540
25.2.2. Installing ABRT for the Command Line 540
25.2.3. Installing Supplementary ABRT Tools 540
25.2.4. Starting the ABRT Services 541
25.2.5. Testing ABRT Crash Detection 541
25.3. CONFIGURING ABRT 542
25.3.1. Configuring Events 542
25.3.2. Creating Custom Events 545
25.3.3. Setting Up Automatic Reporting 547
25.4. DETECTING SOFTWARE PROBLEMS 548
25.4.1. Detecting C and C++ Crashes 549
25.4.2. Detecting Python Exceptions 549
25.4.3. Detecting Ruby Exceptions 550
25.4.4. Detecting Java Exceptions 550
25.4.5. Detecting X.Org Crashes 550
25.4.6. Detecting Kernel Oopses and Panics 550
25.5. HANDLING DETECTED PROBLEMS 551
25.5.1. Using the Command Line Tool 551
25.5.2. Using the GUI 552
25.6. ADDITIONAL RESOURCES 553
Installed Documentation 553
Online Documentation 553
See Also 553
26.1. INTRODUCTION TO GRUB 2 556
Menu Entries in grub.cfg 556
26.2. CONFIGURING GRUB 2 557
26.3. MAKING TEMPORARY CHANGES TO A GRUB 2 MENU 557
26.4. MAKING PERSISTENT CHANGES TO A GRUB 2 MENU USING THE GRUBBY TOOL 558
Listing the Default Kernel 558
Changing the Default Boot Entry 558
Viewing the GRUB 2 Menu Entry for a Kernel 558
Adding and Removing Arguments from a GRUB 2 Menu Entry 559
Updating All Kernel Menus with the Same Arguments 559
Changing a Kernel Argument 559
26.5. CUSTOMIZING THE GRUB 2 CONFIGURATION FILE 560
26.5.1. Changing the Default Boot Entry 561
26.5.2. Editing a Menu Entry 562
26.5.3. Adding a new Entry 562
26.5.4. Creating a Custom Menu 563
26.6. PROTECTING GRUB 2 WITH A PASSWORD 564
Table of Contents
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PART VIII. SYSTEM BACKUP AND RECOVERY
CHAPTER 27. RELAX-AND-RECOVER (REAR)
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CHAPTER 28. CHOOSING SUITABLE RED HAT PRODUCT
CHAPTER 29. RED HAT CUSTOMER PORTAL LABS RELEVANT TO SYSTEM ADMINISTRATION
592
593
Configuring GRUB 2 to Require a Password only for Modifying Entries 565
Configuring GRUB 2 to Require a Password for Modifying and Booting Entries 565
Passwords Set Before Updating to Red Hat Enterprise Linux 7.2 566
Additional GRUB 2 Users 566
26.7. REINSTALLING GRUB 2 566
26.7.1. Reinstalling GRUB 2 on BIOS-Based Machines 566
26.7.2. Reinstalling GRUB 2 on UEFI-Based Machines 566
26.7.3. Resetting and Reinstalling GRUB 2 567
26.8. UPGRADING FROM GRUB LEGACY TO GRUB 2 567
Upgrading from GRUB Legacy to GRUB 2 after the in-place upgrade of the operating system 567
Generating the GRUB 2 configuration files 568
Testing GRUB 2 with GRUB Legacy bootloader still installed 569
Replacing GRUB Legacy bootloader on systems that use BIOS 570
Removing GRUB Legacy on systems that use EFI 570
26.9. GRUB 2 OVER A SERIAL CONSOLE 571
26.9.1. Configuring GRUB 2 for a single boot 571
26.9.2. Configuring GRUB 2 for a persistent change 572
26.9.3. Configuring a new GRUB 2 file 572
26.9.4. Using screen to Connect to the Serial Console 572
26.10. TERMINAL MENU EDITING DURING BOOT 573
26.10.1. Booting to Rescue Mode 573
26.10.2. Booting to Emergency Mode 573
26.10.3. Booting to the Debug Shell 574
26.10.4. Changing and Resetting the Root Password 575
26.11. UNIFIED EXTENSIBLE FIRMWARE INTERFACE (UEFI) SECURE BOOT 578
26.11.1. UEFI Secure Boot Support in Red Hat Enterprise Linux 7 578
Restrictions Imposed by UEFI Secure Boot 579
26.12. ADDITIONAL RESOURCES 579
Installed Documentation 579
Installable and External Documentation 579
27.1. BASIC REAR USAGE 581
27.1.1. Installing ReaR 581
27.1.2. Configuring ReaR 581
ISO-specific Configuration 582
27.1.3. Creating a Rescue System 582
27.1.4. Scheduling ReaR 583
27.1.5. Performing a System Rescue 583
27.2. INTEGRATING REAR WITH BACKUP SOFTWARE 587
27.2.1. The Built-in Backup Method 587
27.2.1.1. Configuring the Internal Backup Method 587
27.2.1.2. Creating a Backup Using the Internal Backup Method 589
27.2.2. Supported Backup Methods 590
27.2.3. Unsupported Backup Methods 590
27.2.4. Creating Multiple Backups 590
iSCSI Helper 593
NTP Configuration 593
Red Hat Enterprise Linux 7 System Administrator’s Guide
18
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CHAPTER 30. REVISION HISTORY
Samba Configuration Helper
VNC Configurator
Bridge Configuration
Network Bonding Helper
LVM RAID Calculator
NFS Helper
Load Balancer Configuration Tool
Yum Repository Configuration Helper
File System Layout Calculator
RHEL Backup and Restore Assistant
DNS Helper
AD Integration Helper (Samba FS – winbind)
Red Hat Enterprise Linux Upgrade Helper
Registration Assistant
Rescue Mode Assistant
Kernel Oops Analyzer
Kdump Helper
SCSI decoder
Red Hat Memory Analyzer
Multipath Helper
Multipath Configuration Visualizer
Red Hat I/O Usage Visualizer
Storage / LVM configuration viewer
30.1. ACKNOWLEDGMENTS